WO2011154450A1

WO2011154450A1 - Assembly for the production of containers by means of a plant comprising an air recycling circuit and recycling method

Info

Publication number: WO2011154450A1
Application number: PCT/EP2011/059495
Authority: WO
Inventors: Eric Adriansens
Original assignee: Sidel Participations
Priority date: 2010-06-10
Filing date: 2011-06-08
Publication date: 2011-12-15
Also published as: FR2961124A1; FR2961124B1

Abstract

The present invention relates to a recycling method and to an assembly comprising a plant (10) which, installed in an industrial area (16) of volume (V), includes a circuit (62) for recycling the cooling air used in the oven (26), said circuit (62) being capable of recycling at least part of the filtered air extracted by extraction means (54) by reintroducing said air into the industrial area (16).

Description

"Assembly for the production of containers by means of an installation comprising an air recycling circuit and recycling process"

The present invention relates to an assembly for the production of containers by means of an installation comprising an air recycling circuit and a recycling process.

The present invention relates more particularly to an assembly for the production of containers comprising at least:

- a building with a closed industrial premises delimiting a volume of ambient air;

- An installation for the manufacture of containers from thermoplastic preforms which is located in said industrial premises, the installation comprising:

• a protective enclosure intended to isolate an interior volume of the installation relative to the ambient air and the installation comprising arranged in said interior volume at least:

A preform thermal conditioning unit comprising an oven that comprises heating means and at least one air cooling device, said cooling device comprising air supply means that are able to draw ambient air through the industrial premises and which are associated with filtration means for filtering said pulsed ambient air in order to deliver, at least in one mode of production of the installation, filtered air to ensure cooling of at least a portion of the preforms by transit inside a zone of the furnace, called zone of thermal conditioning of the preforms, and

• an air extraction system associated with the oven which comprises extraction means adapted to extract the cooling air from said oven area and to evacuate said air after cooling.

Such an assembly is known from the state of the art, in particular factories or production units, for the production of containers forming a hollow body, in particular bottles, flasks, etc. The containers are made from preforms or blanks previously obtained by injection of thermoplastic material, for example PET (PolyEthylene terephthalate), these preforms being then thermally conditioned and then converted into the manufacturing facility of said assembly for production.

Such an installation for manufacturing containers from thermoplastic preforms generally comprises, in addition to at least one thermal conditioning unit, at least one preform conversion unit into containers and a container filling unit obtained from said transformed preforms. , said units also being arranged in the interior volume delimited by the protection enclosure of the installation.

The preforms are conditioned thermally in a furnace forming the thermal conditioning unit of the installation to allow their subsequent processing into a container in the next unit, in particular by a forming operation by means of a fluid under pressure.

The forming operation of the preform is for example carried out by means of a gas under pressure, such as air, to obtain the container by blowing or by stretch-blow molding or at least partly by filling by means of a liquid under pressure.

The thermal conditioning requires the combined application, during a given period of time, of heating on the body of the preform, for example by infrared radiation emitted by the heating means and also an air cooling of said body.

Air cooling has the effect of promoting radiation heating by moderating the effects of heat conduction through the air mass contained in the oven so as to avoid any crystallization and allow the establishment of a gradient in the wall body that is such that the wall has temperature on its inner surface greater than or equal to the temperature of its outer surface.

This is the reason why the furnace of such an installation comprises an air cooling device intended to cool, by applying a flow of cooling air, at least the body of the preforms that pass through the parade, following a determined heating path, inside a zone of the furnace, called thermal conditioning zone which forms at least part of the interior volume delimited by the enclosure.

In addition to air supply means for establishing said flow of cooling air inside the thermal conditioning zone of the oven, the cooling device comprises air filtration means which are associated with said cooling means. 'food.

The filtration means are intended to eliminate, from the ambient air taken from the industrial premises, the impurities (dust, micro-organisms, etc.) so as to deliver to the preforms a cooling air which is a filtered air having a degree of cleanliness as high as possible.

According to the state of the art for the applicant, the oven is also equipped with an air extraction system for extracting the air, after cooling, to evacuate said air to the outside of the industrial premises of implantation of the installation, generally to the atmosphere so as to evacuate with this air the calories resulting from the heating carried out in the oven.

To do this, the extraction system comprises extraction means, such as a fume hood, and an air exhaust duct, one end of which is connected to the extraction means and the other end of which opens out. outside the industrial premises, especially in the atmosphere.

Therefore, respectively drawn from the industrial premises by the supply means and filtered by the filtering means of the cooling device fitted to the oven, the ambient air is then discharged through the extraction system outside the industrial premises. especially to evacuate the heat.

By way of non-limiting example, reference can be made to EP-A-2,191,953 concerning an oven for the thermal conditioning of preforms.

With respect to the present invention, the applicant first discovered that the origin of many problems, all particularly of cleanliness of the manufactured containers, were attributable to the importance of the exchanges of air occurring in the industrial premises of installation of the installation and then that these exchanges of air entering / leaving in the local are related to the consumption in ambient air of the cooling device and the associated extraction system.

Indeed, the ambient air sucked by the supply means of the cooling device is then removed, after cooling, to the outside of the industrial premises by the extraction means and in particular to the atmosphere, but this evacuated air is instantly replaced in the industrial premises by an equivalent volume of air.

Thus, at least part of the ambient air contained in the industrial premises is constantly renewed by air coming from outside the industrial premises, mainly by atmospheric air outside the building. factory building or production complex housing the industrial premises.

An incoming volume of atmospheric air consequently replaces in the total volume of the industrial space the volume of ambient air that has been taken or drawn from it before being discharged to the outside by the extraction system.

However, atmospheric air entering the industrial premises from outside is an air with uncontrolled and generally very variable quality parameters.

More precisely, the temperature of the air, its degree of humidity or, above all, the undesirable presence of bacteria such as dust are not controlled and are all parameters of which it is however perfectly acquired that they directly influence the quality. of the manufacture of the containers.

Moreover, such parameters vary according to the geographical location of the building including the installation, see - for the same location - depending on the season which is likely to modify some of these qualitative parameters such as the temperature of the air which can vary with a strong amplitude on the same day.

The aforementioned problems are therefore essentially the impact of variations in the qualitative parameters (temperature, humidity, etc.) of atmospheric air renewing the ambient air leaving the industrial premises that affect the thermal conditioning process but still and especially the cleanliness (dust, bacteria, ...) of this air.

Indeed, given the volume of atmospheric air entering, the applicant has been able to establish that this renewal of the ambient air, instead of the air evacuated, by this atmospheric air generally not clean leads to a degradation of the means filtering implemented, see incidentally the quality of manufacture of the containers, especially the cleanliness of the final containers.

The exchanges of air entering / leaving the industrial premises have, among other consequences, a rapid fouling of the filtration means of the cooling device resulting in a decrease in their efficiency or at least a reduction in the duration of use of the means of cooling. filtration and an increase in the frequency of maintenance operations requiring a complete shutdown of the manufacturing facility.

These air exchange problems therefore also have a direct economic impact on the operating costs of the container manufacturing facility.

To control the quality of the ambient air of the industrial premises, it is possible to resort to a transformation of the industrial premises to make what is commonly called a "clean room", that is to say a sealed enclosure arranged for to eliminate as much as possible dust and micro-organisms, to obtain ultra-clean manufacturing industrial conditions in the industrial premises.

However, it will be readily understood that if such a transformation is still possible, the costs associated both for the transformation of the industrial premises and later for the operation of the installation are very expensive.

In addition, however, only a part of the problems related to the quality of manufacture are solved when operating costs will be increased including all costs corresponding to the means implemented to achieve such a room. white. The purpose of the present invention is in particular to overcome the aforementioned drawbacks and to provide a particularly economical installation to the farm, while improving the quality of the containers and more particularly the cleanliness of the containers manufactured.

For this purpose, the invention proposes an assembly for the production of containers of the type described above, characterized in that the installation comprises a recirculation circuit of the cooling air adapted to recycle at least a portion of the filtered air extracted by said extraction means by reintroducing said air into the industrial premises.

Advantageously, the filtered and extracted air, called recycled air, is reintroduced directly into the volume of the industrial premises of installation of the installation.

Advantageously, a recycling circuit according to the invention makes it possible to recycle the air filtered by the air cooling device fitted to the oven, that is to say to use again directly "looped" the filtered air after its first use in the oven for cooling purposes.

The recycled cooling air has particularly advantageous qualities with respect to the air, in particular atmospheric air, previously admitted in the industrial space to compensate for the air completely evacuated, to the atmosphere, outside the industrial premises. .

In fact, recycled air presents above all a particularly high degree of cleanliness, dust, bacteria, etc. having been removed during the filtration operation performed by the filtering means of the cooling device.

In addition, during its passage through the oven, the cooling air dries under the effect of the heat prevailing inside the oven so that we obtain a dehumidification of the air without having to use additional means.

Thanks to the recycling according to the invention, it eliminates the renewal of the ambient air by entering air whose parameters were not controlled and it ensures the renewal with filtered air, or by a recycled air with all especially a high degree of cleanliness. Advantageously, the parameters of the ambient air of the industrial premises are therefore better controlled so that the quality of the containers produced by the installation is improved.

Advantageously, the recycling circuit is provided with means for regulating the temperature of the recycled air, alternatively the industrial premises is provided with such means for regulating the temperature of the ambient air, in order to maintain the air temperature in the room. a range of temperature values ensuring optimum manufacturing conditions.

According to the invention, recirculated air is reintroduced into the industrial premises in place of the ambient air consumed by the supply means of the cooling device and the recycled air that renews the ambient air is therefore susceptible of to be used again, in particular again by these same means of supplying the cooling device and so on following a loop circulation of air between the industrial premises and the inside of the oven.

Advantageously, the recycling circuit according to the invention makes it possible to treat the ambient air by using existing means so that there is no need to resort to specific additional means, such as those of a clean room.

Moreover, thanks to such a circuit and the recycling process, the ambient air contained in the industrial premises is an air whose cleanliness will increase with the operating time of the installation.

Indeed, the ambient air drawn by the furnace cooling device in the industrial premises is cleaner to each of its passages through filtration means of said cooling device.

Advantageously, the extraction means of the recycling circuit are put into operation for a given period of time before the manufacture of the containers actually begins and this in order to improve the cleanliness of the ambient air contained in the industrial premises.

Thus, when the thermal conditioning of the preforms begins in the manufacturing plant, followed by the transformation of the preforms into containers, the ambient air drawn by the device cooling is then an air with a high degree of cleanliness having been previously filtered, the degree of cleanness being determined in particular by the filtration means implemented.

In general, the degree of cleanliness is one of the quality parameters, in particular very controlled in the context of agri-food applications using such containers.

In addition, the fouling of all the filtration means equipping the facility is reduced and their effectiveness as their service life increased to the benefit of a reduction in associated operating costs.

Advantageously, the recycling circuit according to the invention thus also makes it possible to obtain substantial economic benefits, in particular because of the reduction in the frequency between the maintenance operations or changes in the filtration means and the increase in the overall duration of use of the filtration means.

According to other features of the invention:

- The recycling circuit comprises at least extraction means for extracting the filtered air introduced into the furnace by the air cooling device;

- The recycling circuit comprises at least one main pipe, an upstream end is connected to the extraction means and a downstream end opens into the industrial premises to reintroduce said filtered air extracted from the furnace area;

the means for extracting the recycling circuit comprise at least one hood which, with a complementary part of the enclosure, is able to confine said zone of the oven to isolate it from the ambient air and at least one fan capable of extracting the filtered air present in said zone of the oven to recycle said air in the industrial premises via said recycling circuit;

the recycling circuit comprises at least one evacuation pipe whose one end is connected to the extraction means and the other end of which opens out from the industrial premises, in particular into the atmosphere, and the recycling circuit comprises regulating means which are capable of selectively distributing the extracted air in the evacuation duct and / or in the main duct; - The recycling circuit comprises at least one control unit adapted to control the extraction means and the supply means so that the volume of air extracted by the extraction means is greater than the volume of ambient air pulsed by the supply means of the cooling device in the volume industrial premises;

the recycling circuit comprises air cooling means which are capable of being selectively controlled to regulate the temperature of the recycled air so that the temperature of said recycled air, intended to be reintroduced into the industrial premises, is lower or equal to a set temperature determined to maintain the ambient temperature of the air in the industrial premises in a given temperature range;

the extraction means are capable of establishing a circulation of air in a loop between the volume of the industrial premises and the part of the internal volume formed by the zone of the furnace with a factor corresponding to the ratio of the volume of air extracted out of said zone of the furnace by the extraction means on the volume of the industrial premises which, for a given unit operating time, is greater than or equal to 1;

- The extraction means are controlled so as to establish a factor between 2 and Vi.

Preferably, the extraction means are controlled so as to establish a factor of between 8 and 12.

The invention also proposes an air recycling recycling process in an assembly for the production of containers which comprises a building comprising a closed industrial premises delimiting a volume of ambient air, and an installation for the manufacture of containers from of preforms which is implanted in the industrial premises, the recycling process comprising at least the steps consisting successively of:

(a) filtering ambient air to obtain filtered air suitable for use in air cooling at least a portion of the preforms during thermal conditioning in an oven of the installation; (b) extracting the filtered air out of the oven after using said air for cooling;

(c) recycling at least a portion of said filtered air extracted from the furnace by reintroducing at least a portion of said air into said industrial premises.

Thanks to the air recycling process, it eliminates the air exchange phenomenon during which the ambient air is renewed by atmospheric air and the degree of cleanliness of the air is particularly increased and therefore that of manufactured containers.

Advantageously, the recycling process comprises at least one step of controlling the extraction means to establish a loop air circulation between the volume of the industrial premises and an area inside the oven with a factor corresponding to the ratio of volume of air extracted from said zone of the furnace by the extraction means on the volume of the industrial premises which, for a given unit operating time, is greater than or equal to 1.

Advantageously, the steps of the recycling process are implemented in an installation comprising a recycling circuit according to the teachings of the invention.

Other characteristics and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended drawings in which:

- Figure 1 is a schematic view from above which partially represents an example of an assembly for the production of containers comprising a container manufacturing installation located in an industrial premises of a building of said assembly;

FIG. 2 is a perspective view which represents the assembly according to FIG. 1 and which illustrates the recycling circuit according to one embodiment of the invention;

- Figure 3 is a cross sectional view showing the oven and illustrating said embodiment of the recycling circuit according to the invention.

In the description and the claims, the terms "front" or "rear" will be adopted by convention and in a nonlimiting manner with reference to the longitudinal direction, "upper" and "lower", with reference to the vertical direction and according to the gravity terrestrial longitudinal, vertical and transverse directions with reference to the trihedrons (L, V, T) indicated in the figures.

The terms "upstream" and "downstream" will be used with reference to the flow direction of the air flow in the installation and / or in the air recycling circuit.

FIG. 1 shows diagrammatically an assembly 5 for the production of containers 12 from a thermoplastic preform 14.

The assembly 5 or production plant comprises a building (not shown) comprising a closed industrial premises 16 delimiting a volume V of ambient air and an installation 10 for the manufacture of said containers 12 which is located in said industrial premises 16.

By industrial premises 16 "closed" means here enclosed by walls and a roof so that the volume V is determinable, so closed does not mean that the room is devoid of access means (such as doors), the Industrial premises 16 is therefore not "open to all winds" so that the volume V of ambient air effectively constitutes an external environment around the installation 10.

Figures 1 and 2 illustrate, without limitation, an embodiment of such an assembly 5 and, more particularly for Figure 1, the installation 10 according to the state of the art for the applicant.

FIG. 1 shows in detail an example of preform 14 for the manufacture of a container 12 forming a hollow body, such as here a bottle, intended to be thermally conditioned and then transformed to obtain said container 12.

By definition, the term "container" hereinafter denotes both the final container obtained by a single-stage forming process of a preform directly leading to the final container, such as the bottle illustrated in detail. in Figure 1, an intermediate container obtained in the case of implementation of a forming process with several stages of transformation.

The installation 10 is located in an industrial premises 16 advantageously closed located within a building (not shown) of a production unit 5, the ambient air contained in the industrial premises 16 of volume V constituting the external environment around the installation 10.

For the implementation of the present invention, it is important that the industrial premises 16 is closed as explained above and this in order to constitute for the installation 10 a "reservoir" of ambient air, of given volume V.

Advantageously, the installation 10 comprises at least one enclosure 18 for protecting the installation intended to isolate, with respect to the ambient air of the industrial premises 16 for the installation of the installation 10, an internal volume Vi inside. which are arranged the different means of manufacturing the containers 12.

The installation 10 comprises a preform feeding system 22, not shown in detail.

Alternatively, the installation 10 may be provided with a decontamination module by applying a sterilizing agent to treat the preforms 14, in particular by means of a jet of dry steam to cause condensation deposition. a uniform steaming film of sterilizing agent on at least the inner wall of the preforms 14 to be sterilized.

The installation 10 comprises at least one thermal conditioning unit constituted by at least one oven 26.

The supply system 22 is arranged upstream of an inlet E of the oven 26, arranged in the enclosure 18 of protection, at which the preforms 14 are transferred by a transfer wheel 24 to a conveying device 28 equipping the oven 26.

The conveying device 28 is for example constituted by an endless chain carrying means for supporting the preforms 14, for example "spinettes", said device 28 being intended to transport the preforms 14 along a determined heating path ending at the oven outlet 26.

In a nonlimiting manner, the furnace 26 here has a "U" heating path comprising two parallel longitudinal heating sections, one go, the other return, interconnected by a transverse curvilinear section, said stabilization.

The thermal conditioning unit of the installation 10 formed by the furnace 26 mainly comprises heating means 30 and at least one air cooling device 34, said device 34 being intended to cool by air at least a portion of the preforms 14, such as the body (and the bottom).

Advantageously, the cooling device 34 is able to cool by air on the one hand the bodies of the preforms 14 in transit along the heating path and, on the other hand, the necks of the preforms 14 as well as the adjacent mechanical members, while particularly the means for supporting the preforms 14.

The cooling device 34 comprises means 32 for supplying air, such as fans, arranged to deliver said cooling air over all or part of the heating path.

The cooling device 34 comprises filtering means 36 for filtering the air intended for cooling.

Preferably, the support means ("spinners") of the conveying device 28 are able to rotate each of the preforms 14 in order to promote an appropriate distribution of the heat in the body of each preform 14.

After their thermal conditioning by the oven 26, the preforms 14 are transported from the outlet of the oven 26 to a unit 38 for converting the preforms 14 into containers 12, for example by means of at least one transfer wheel 35. .

Advantageously, the processing unit 38 is here constituted by a blowing machine (called "blower").

In the example shown in FIG. 1, the blowing machine is of the rotary type and comprises a carousel 40 equipped with a plurality of stations which are distributed circumferentially and which are each provided mainly with means 42 for molding and, for example, with means additional blowing or stretch-blow molding (not shown).

Preferably, the containers 12 obtained are then transported, for example by transfer wheels 44, 46, to a filling unit 48.

Advantageously, the filling unit 48 comprises at least one filling machine 50 and preferably also a sealing machine 52, said machines 50, 52 (not shown in details) being able to successively fill the containers 12 and then to close the filled containers 12, for example by means of screw caps complementary to the necks.

Preferably, the filling unit 48 is juxtaposed with the processing unit 38 so as to obtain a compact installation in which the entire manufacturing process is carried out until final delivery of filled and closed containers 12. , see labeled.

The containers 12 are for example conveyed to an outlet S by a transfer wheel 51 and are then capable of being packaged, in particular batched, packaged and palletized, for their shipment for marketing purposes.

As illustrated in FIG. 1, the enclosure 18 of the installation 10 delimits a general internal volume Vi in which all the units 26, 38, 48 are arranged for the manufacture of the containers 12 which have just been described and which are thus confined, isolated from the ambient air of the industrial premises 16 forming the external environment around the installation 10.

The enclosure 18 (represented by a strong line in FIG. 1) is constituted for example by a set of vertical walls formed by panels and at least one horizontal wall to form a ceiling covering the entire installation 10.

Part of the enclosure 18 of protection delimits with the furnace 26 a zone 20, said zone of thermal conditioning of the preforms 14, forming at least a part of the internal volume Vi and into which the filtered air is introduced for cooling at least part of the preforms 14 in transit inside the oven 26.

Advantageously, the installation 10 comprises an air extraction system associated with the oven 26 which comprises extraction means 54 able to extract the cooling air from the oven 26, or outside said zone 20 of the internal volume Vi , and evacuate said air after use for cooling.

For this purpose, the extraction system comprises, for example, a discharge duct 56, the outlet of which opens out from the industrial premises 16, generally into the atmosphere. Preferably, the extraction means 54 comprise at least one extraction hood 58 incorporating ventilation means 60, such as at least one fan.

When the installation 10 is already provided with such an extraction system the implementation of an air recycling circuit according to the invention is particularly facilitated when said circuit is likely to be obtained by modifying such an existing extraction system.

With reference to FIGS. 2 and 3, a plant 10 of the type previously described in FIG. 1 and installed in an industrial premises 16 of volume V will now be described more particularly, said installation 10 illustrating in a nonlimiting manner an embodiment of a recycling circuit 62 according to the invention.

According to the invention, the installation 10 comprises a circuit 62 for recycling the cooling air which is able to recycle at least a portion of the filtered air extracted by extraction means 54, such as said means 54. extraction, reintroducing said air into the industrial premises 16.

Advantageously, the filtered air extracted by said extraction means 54 is directly reintroduced into the industrial premises 16.

Advantageously, the recycling circuit 62 comprises extraction means, such as said extraction means 54, for extracting the filtered air introduced into the furnace 26 by the air cooling device 34 in order to recycle said filtered air in the recycling circuit 62 and reintroducing it directly into the industrial premises 16.

When the installation 10 is of the type described above, the recycling circuit 62 is made by modifying the prior extraction system. However, it is a new application of the prior means to obtain a recycling circuit 62 according to the invention.

The means 54 for extracting air are here intended to extract the cooling air outside said zone 20 of the furnace 26 in which the preforms 14 are thermally conditioned and which forms a part of said internal volume Vi delimited by the part of the enclosure 18 surrounding the oven 26 and according to the invention to extract said air for allow the recycling of this air in the volume V of the industrial premises 16 and no longer to the outside, that is to say to the atmosphere.

Preferably, the means 54 for extracting the recycling circuit 62 comprise at least one hood, such as the hood 58.

The hood 58 is complementary to a portion of the chamber 18 so as to confine the zone 20 of the oven 26 to isolate it from the ambient air.

Advantageously, the extraction means 54 comprise at least one fan 60 adapted to extract by vacuum the filtered air present in the zone 20 of the oven 26 to allow the recycling of said air in the industrial premises 16.

Preferably, the recycling circuit 62 comprises at least one main duct 64, an upstream end of which is connected to the extraction means 54 and a downstream end of which opens into the industrial premises 16 in order to reintroduce the filtered air extracted from the outlet. oven 26.

When the recirculation circuit 62 comprises a discharge duct 56, the main duct 64 is advantageously connected to said evacuation duct 56.

Such exhaust duct 56 may be maintained or removed in the desired configuration of the recycling circuit 62.

Thus, in the event of the removal of a downstream portion of the evacuation conduit 56 intended to convey the extracted air to the outside, the upstream portion of the conduit 56 remaining advantageously constitutes said main conduit 64.

As illustrated in FIG. 2, the recirculation circuit 62 preferably comprises at least one evacuation duct 56, one end of which is connected to the extraction means 54, in particular the hood 58, and the other end of which opens out at the end. outside the industrial premises 16, especially in the atmosphere, the main conduit 64 of the circuit 62 being connected to the conduit 56 for evacuation.

Preferably, the main conduit 64 of the circuit is connected to the evacuation conduit 56, downstream of the junction of the evacuation conduit 56 with the extractor hood 58.

Advantageously, the recycling circuit 62 then comprises means 66 for regulating the flow of air which are able to distribute selectively extract air in the outlet duct 56 and / or in said main duct 64.

The regulation means 66 consist, for example, of at least one flap which is mounted inside at least one duct of the recycling circuit 62, here at the connection junction between the evacuation duct 56 and the duct. main duct 64, so as to selectively close the flow of air flow in one or other of the conduits 56, 64.

Preferably, the flap 66 forming the regulation means is pivotally mounted between at least two extreme positions, a first position P1 and a second position P2.

In the first position P1 shown in strong lines in FIG. 3, the shutter 66 completely closes the section of the evacuation duct 56 so that the extracted air flow then circulates integrally in the main duct 64 so as to be recycled in the industrial premises 16.

In the second position P2 shown in dashed line in FIG. 3, the flap 66 extends vertically and completely closes the section of the main duct 64 so that the extracted air flow then circulates integrally in the evacuation duct 56 outside the industrial premises 16, no recycling is then performed in the room.

The flap 66 is able to occupy intermediate positions between the said extreme positions P1 and P2, such as the position PO illustrated in FIG. 3, so that the recycling is then partial and only a part of the filtered airflow extracted is reintroduced in the volume V of the industrial premises 16.

Advantageously, an evacuation duct 56 and regulation means 66 implemented can be used to achieve a thermal regulation of the recycled air by means of the recycling circuit 62.

Advantageously, the recycling circuit 62 comprises air cooling means 68 which can be selectively controlled to regulate the temperature of the air.

Preferably, the cooling means 68 consist of an air-fluid type heat exchanger which is suitable for cooling the recycled air passing through with a heat transfer fluid, for example water with or without additive.

The cooling means 68 are for example arranged in the main duct 64 of the recycling circuit 62, upstream of the outlet of said duct 64 through which the filtered air extracted, said recycled, is reintroduced into the industrial premises 16.

Thanks to such means 68 for cooling the recycled air, the recycling circuit 62 is able to control the temperature of said air intended to be reintroduced into the industrial premises 16, so that the temperature of said air is less than or equal to set temperature determined in order to maintain the ambient temperature of the air in said industrial premises 16 in a given range of temperatures, for example between 15 ° C and 35 ° C, preferably around Vi ° C.

Advantageously, the regulation means 66 are able to be controlled in combination with said cooling means 68 for regulating the ambient air temperature of the industrial premises 16 in the volume V of which all or part of the air is recycled by the intermediate of the recycling circuit 62.

Advantageously, the recycling circuit 62 comprises at least one control unit 70 able to control the extraction means 54 and the supply means 32.

Preferably, the recycling circuit 62 comprises at least one control unit able to control the regulation means 66 and / or the cooling means 68, said unit being for example constituted by the control unit 70.

The means 60 for ventilating the extraction means 54 are driven by a motor 72.

Advantageously, the motor 72 for driving the means 60 for ventilating the extraction means 54 is associated with a speed variator 74 which is able to be controlled by the control unit 70.

The means 32 for supplying air to the cooling device 34 consist, for example, of at least one fan 76 which is driven by a motor 78. Advantageously, the motor 78 for driving the supply means 32 is associated with a speed variator 80 which can be controlled by the control unit 70.

Advantageously, the control unit 70 of the recycling circuit 62 is able to control the extraction means 54 by controlling the speed variator 74 associated with the motor 72 driving the ventilation means 60 and to drive the power supply means 32. controlling the speed variator 80 associated with the motor 78 driving the fan 76.

Advantageously, the control unit 70 drives the dimmers

74 and 80 so that the volume Ve of air extracted by the extraction means 54 is greater than the volume Va of ambient air drawn by the supply means 32 of the cooling device 34 in the industrial premises 16 of volume V .

To do this, the control unit 70 operates at least one signal S1 representative of the extracted air flow that is provided by at least one sensor 82 arranged in the recycling circuit 62, for example downstream of the fan 60, and a signal S2 representative of the air flow sucked by the supply means 32 and which is provided by at least one sensor 84 preferably arranged in the cooling device 34, downstream of the filtering means 36.

Advantageously, the filtering means 36 of the cooling device 34 are constituted by so-called "absolute" filters, such as "ULPA" or "HEPA" type filters.

It will be recalled that a filter "ULPA" acronym for "Ultra Low

Air Penetration "in English is called in French: very low penetration air filter, and a filter" HEPA "acronym for" High Efficiency Particulate Air "in English is called in French: air filter very high efficiency.

Preferably and as illustrated by the cross section of the oven 26 in FIG. 3, the filtration means 36 comprise at least one pre-filter 86 which is here arranged in the vicinity of an inlet mouth 88 disposed in the enclosure 18 and a filter 90 arranged downstream of the pre-filter 86, the passage section of the pre-filter 86 being greater than the passage section of the filter 90. Preferably, the pre-filter 64 is a gravimetric filter, which is capable of filtering so-called coarse particles, which are of a determined diameter, for example greater than ten microns.

Advantageously, the filter 68 is an "absolute" filter of one of the aforementioned types, which is capable of filtering so-called fine particles, for example with a diameter greater than one micron.

We will now more particularly describe the operation of the recycling circuit 62 according to the embodiment of the invention.

In the installation 10, the circulation of the air in the oven 26 begins with the suction of ambient air which is taken from the volume V of the industrial space 16 by the air supply means 32 of the device 34 cooling.

More specifically, the ambient air is sucked by the depression caused by the rotation of the fans 76 that includes the oven 26 and which are for example distributed longitudinally as shown in Figure 1.

The sucked ambient air successively passes through the inlet mouths 88, the pre-filters 86 and the filters 90 until a plenum 92 of the cooling device 34 forms a filtered air reservoir for cooling.

The corresponding air flow is illustrated in FIGS. 2 and 3 by arrows "A" through the cooling circuit formed by the means of the air cooling device 34 of at least a portion of the preforms 14.

Inside the furnace 26, the filtered air is brought to the zone 20 for thermal conditioning of the preforms 14 in which the heating means 30 are arranged and in which said filtered air comes into contact in particular with the bodies of the preforms. to effect cooling of the outer surface of the body wall.

The cooling air is then withdrawn from the furnace 26, from the zone 20 of the furnace 26, by the means 54 for extracting air from the recycling circuit 62.

Preferably, and as shown in FIG. 3, the flap 66 occupies the position P1 in which it closes off the section of the evacuation duct 56 so that the air extracted by the fan 60 from the extraction means 54 travels leads 64 of circuit 62 of recycling until its reintroduction in the volume V of the industrial premises 16.

When the flap 66 occupies said position P1, the circulation of the recycled air is carried out as it would be in a recycling circuit 62 without evacuation conduit 56 and having only a main conduit 64.

Advantageously, the filtered air thus extracted is then completely reintroduced into the industrial premises 16 for implantation by the recycling circuit 62.

As explained above, the quantity of ambient air drawn from the industrial premises 16 by the cooling device 34 of an installation 10 is returned to the industrial premises 16 in the form of recycled air, which is advantageously filtered air whose degree of cleanliness is much higher than the initial one of the ambient air.

Advantageously, the invention proposes recycling the cooling air extracted from the oven in order to suppress the renewal of ambient air by atmospheric air, while advantageously taking advantage of the fact that this air is filtered air to improve the air quality. quality of the containers manufactured and especially the degree of cleanliness.

The invention also proposes a method for recycling air in a container production assembly comprising a building comprising a closed industrial premises 16 delimiting a volume V of ambient air, and an installation 10 for the manufacture of containers 12 from preforms 14 which is implanted in the industrial premises 16, the recycling process comprising at least the steps consisting successively of:

(a) filtering ambient air to obtain a filtered air used for air cooling at least a portion of the preforms 14 during the thermal conditioning carried out in an oven 26 of the installation 10;

(b) extracting the filtered air out of the oven 26 after using said air for cooling;

(c) recycling at least a portion of said filtered air extracted from the furnace 26 by reintroducing at least a portion of said air into said industrial premises 16. According to the recycling process according to the invention, the air filtered by the cooling device 34 is recycled, that is to say introduced directly into the industrial premises 16 for the installation of the installation 10 so that it can be used again, in loop, as ambient air.

Thanks to the invention, the ambient air contained in the industrial premises 16 is an air whose cleanliness will increase with the operating time of the installation 10, dust, bacteria, etc. being eliminated by successive filtration operations.

Advantageously, the quality of the ambient air resulting from the implementation of recycling according to the invention makes it possible to increase the quality of manufacture of the containers obtained with such an installation, especially the degree of cleanliness of the containers 12.

Advantageously, a system 94 for blowing air is associated with the unit 38 of transformation here comprising a blowing machine, said system 94 being integrated in an upper part of the enclosure 18 forming a ceiling.

This insufflation system 94 is intended to inject air into the associated part of the internal volume Vi, isolated from the external environment by a part of the chamber 18, and this in order to establish an overpressure to reduce effectively the risks of pollution from outside, including airborne particles.

The insufflation system 94 thus draws from the industrial premises 16 a given volume of ambient air which is symbolized by the arrow "B" in FIG.

A similar air insufflation system 96 equips the filling unit 48 to also establish an overpressure inside the corresponding part of the internal volume Vi delimited by the chamber 18, the ambient air drawn from the industrial premises 16 by the insufflation system 96 is symbolized by an arrow "C" in FIG.

By recycling the cooling air used in the furnace 26 for thermal conditioning, the insufflation systems 94 and 96 draw respectively into the volume V of the industrial premises 16 an ambient air which is cleaner so that the air insufflated for the putting in overpressure is an air whose degree of cleanliness is improved. Advantageously, the degree of cleanliness of the air with which the preforms 14, then the containers 12 are in contact inside the installation is homogeneous through the various units of the installation 10.

Advantageously, the fouling of the filtration means integrated in the insufflation systems 94, 96 is also limited, with the same economic benefits as those detailed above for those 36 of the cooling device 34.

Advantageously, the extraction means 54 are able to establish a circulation of air in a loop between the volume V of the industrial premises 16 and the part of the internal volume Vi formed by the zone 20 of the oven 26 with a factor F corresponding to the ratio of volume Ve of air extracted from said zone 20 of the furnace 26 by the extraction means 54 on the volume V of the industrial premises 16 which, for a given unit operating time, is greater than or equal to one, ie F = 1 .

Advantageously, the given unit operating time is equal to one hour.

Preferably, the factor F = Ve / V is between two [F = 2] and twenty [F = 20].

To do this, the extraction means 54 are controlled by the control unit 70, in particular as a function of the signals S1 and S2.

In order to illustrate the advantages of the invention, the air consumption or flow rates of a manufacturing installation of the type of that described with reference to FIGS. 1 and 2 will be detailed below.

By way of nonlimiting examples, the consumption of air or air flow sucked by an insufflation system 94 is of the order of 8000 m ³ per hour, while that of the insufflation system 96 is order of 10,000 m ³ per hour.

Even more important is the air consumed by the air cooling device 34 associated with the furnace 26 since, for example, values of the order of 20,000 to 30,000 m ³ per hour are attained according to the type of furnace, in particular the furnace. number of heating module.

For a furnace 26 of modular design, the air consumption per heating module is of the order of 1300 m ³ per hour, the furnace may comprise for example twenty modules. The air consumption of an installation 10 is therefore of the order of 30,000 to 50,000 m ³ per hour with generally at least or more than half of the air for the single air cooling device 34 of the oven 26.

It is therefore easy to understand the importance of the problems previously encountered due to the evacuation of the cooling air outside and its replacement with atmospheric air.

Thus, by way of non-limiting example, if we consider an industrial premises 16 generally parallelepipedic having dimensions of 6 m respectively for height, 15 m wide and 30 m long, we obtain a volume of 2700 m ³ .

The volume of 2700 m ³ of ambient air of the industrial premises 16 constitutes a "reservoir" in which the air required for the installation 10 is drawn by the cooling device 34 and is then discharged outside the industrial premises. .

Conversely, the ambient air consumed by the insufflation means 94, 96 for the overpressure of the units 38, 48 escapes in such a way that said air used is permanently returned through the chamber 18.

Considering an air consumption equal to 27,000 m ³ per hour for the only cooling device 34 whose air is now recycled through the recycling circuit 62, this means that the ambient air contained in the volume V of the industrial premises 16 will be renewed more than ten times in one hour of time with recycled air.

In this example, the factor F is therefore equal to ten [F = 10].

The recycling circuit 62 will therefore act as a "lung" to treat the ambient air, particularly the cleanliness of the air, drawing the ambient air before returning it after recycling in the form of filtered air of higher degree of cleanliness.

Advantageously, the factor F is between eight [F = 8] and twelve [F = 12], for example equal to ten [F = 10] as in the previous example.

Advantageously, the recycling according to the invention implements means such as the filtration means 36 of the device 34 of FIG. which are already existing means, at least in the Applicant's facilities.

Thus, there is no need for additional resources and a fortiori a clean room.

Therefore, the implementation of recycling according to the invention offers an alternative solution particularly interesting economically compared to such a clean room.

In fact, in an installation 10 comprising a recycling circuit 62 according to the invention, by eliminating the evacuation of the cooling air towards the atmosphere, the volume V of ambient air of the industrial premises 16 will be renewed with recycled air more and more clean.

Advantageously, the volume Ve of air extracted by the extraction means 54 is greater than the volume Va of ambient air drawn by the supply means 32 of the cooling device 34 in the industrial premises 16 of volume V so as to avoid any ambient air input into the volume Vi through the enclosure 18.

The recirculation of the air according to the invention has the effect of suppressing the call for air which previously led to atmospheric air entering the industrial premises 16 in compensation for the air discharged into the atmosphere .

Advantageously, the recycled air having been filtered by the filtration means 36, the recycled air delivered by the circuit 62 is an air having a degree of cleanliness which, determined by the filtering means employed, is greater than the initial one. 'ambiant air.

Once recycled in the industrial premises 16, this air forms part of the ambient air and is then likely to be sucked in again by the cooling device 34.

It will therefore be understood that at each passage or loop through the recycling circuit 62 of the installation 10, the air output is more clean air.

This is the reason why, the recycling of the air carried out according to the teachings of the invention makes it possible to improve, in operating mode, said production mode, of the installation 10, the quality of the containers 12 manufactured which thus exhibit a particularly high degree of decontamination or sterility. Advantageously, the recycling of the cooling air according to the invention makes it possible to reduce the fouling of the filtering means 36 of the oven cooling device 26, such as filtration means generally integrated with the insufflation systems 94, 96 of the units 48, 38, and thereby reduce the frequency of maintenance interventions.

The quality of the ambient air is substantially increased when the recycled air is still automatically dehumidified by means 30 for heating the oven 26.

Advantageously, the steps (a), (b) and (c) of the recycling process are implemented in a mode of operation, called "out of production", that is to say without preforms 14 being put into operation. circulation inside the oven 26.

The heating means 30 are then active or not.

The heating means 30 are particularly active to achieve drying of the cooling air.

In such a mode out of production, the air sucked is not - in the absence of preforms 14 - used for cooling the bodies but for cooling the mechanical members, such as the support means of the preforms 14 able to rotate on itself ("spinners").

Thus, the step (b) of the recycling process of extracting the filtered air out of the oven 26 is not limited to the case where the air is used, while the heating means are active, for cooling at least a portion of the preforms 14 or only the mechanical members of the transport device 28 for said operating mode out of production.

Advantageously, the means 54 for extracting the recycling circuit 62 are controlled, preferably together with the means 32 for supplying the cooling device 34, to establish a circulation of air in a loop between the industrial premises 16 of volume V and the interior volume Vi of the oven 26.

Such an off-production mode of operation is advantageously implemented before the production begins to improve the cleanliness of the ambient air contained in the volume V of the industrial premises 16. Depending on the factor F, the volume of ambient air filtered by the filtration means 36 before being recycled by the circuit 62 will be more or less important, so after a period of time determined a maximum degree of cleanliness is likely to to be reached before the beginning of the manufacture of the containers 12.

The non-production mode therefore advantageously precedes a production mode in which the plant 10 is in operation to manufacture containers 12, preforms 14 being introduced at the inlet E of the oven 26 for the purpose of their thermal conditioning.

Claims

1. Assembly (5) for the production of containers (12) comprising at least:

- A building comprising a closed industrial premises (16) delimiting a volume (V) of ambient air;

- An installation (10) for the manufacture of containers (12) from thermoplastic preforms (14) which is implanted in said industrial premises (16), the installation comprising:

A protective enclosure (18) intended to isolate an interior volume (Vi) of the installation (10) relative to the ambient air and the installation (10) comprising arranged in said interior volume (Vi) at least:

A preform thermal conditioning unit (14) comprising an oven (26) which comprises heating means (30) and at least one air cooling device (34), said cooling device (34) comprising means ( 32) which are adapted to draw ambient air in the industrial premises (16) and which are associated with filter means (36) for filtering said pulsed ambient air in order to deliver, at least in a production mode of the installation (10), a filtered air for cooling at least part of the preforms (14) in transit inside an area (20) of the oven (26), said zone thermal conditioning of the preforms (14), and

· An air extraction system associated with the oven (26) which comprises extraction means able to extract the cooling air from said zone (20) of the oven (26) and to evacuate said air after cooling,

characterized in that the installation (10) comprises a cooling air recycling circuit (62) adapted to recycle at least a portion of the filtered air extracted by said extraction means (54) by reintroducing said air in the industrial premises (16).

2. An assembly according to claim 1, characterized in that the recycling circuit (62) comprises at least one main conduit (64), an upstream end of which is connected to the extraction means (54) and a downstream end of which opens into the industrial premises (16) to reintroduce said filtered air extracted from the zone (20) of the furnace (26).

3. An assembly according to claim 1, characterized in that the means (54) for extracting the recycling circuit (62) comprise at least one hood (58) which, with a complementary part of the enclosure (18), is capable of confining said zone (20) of the oven (26) to isolate it from the ambient air and at least one fan (60) able to extract the filtered air present in said zone (20) of the oven (26) to recycling said air into the industrial premises (16) via said recycling circuit (62).

4. An assembly according to claim 1, characterized in that the recycling circuit (62) comprises at least one evacuation pipe (56), one end of which is connected to the extraction means (54, 58, 60) and of which the the other end opens out of the industrial premises (16) and in that the recycling circuit (62) comprises regulating means (66) which are capable of selectively distributing the extracted air in the duct (56). evacuation and / or in the main conduit (64).

5. The assembly of claim 1, characterized in that the recycling circuit (62) comprises at least one control unit (70) adapted to control the means (54) of extraction and the means (32) of supply of whereby the volume (Ve) of air extracted by the extraction means (54) is greater than the volume (Va) of ambient air drawn by the means (32) for supplying the cooling device (34), in the industrial premises (16) of volume (V).

6. The assembly of claim 1, characterized in that the recycling circuit (62) comprises means (68) for cooling the air which are capable of being selectively controlled to regulate the temperature of the recycled air so that the temperature of said recycled air, intended to be reintroduced into the industrial premises (16), is less than or equal to a set temperature determined to maintain the ambient temperature of the air in the industrial premises (16) in a given temperature range .

7. The assembly of claim 1, characterized in that the means (54) of extraction are able to establish a circulation of air loop between the volume (V) of the industrial premises (16) and the part of the internal volume (Vi) formed by the zone (20) of the oven (26) with a factor (F) corresponding to the ratio of the volume (Ve) of air extracted from said zone (20) of the oven (26) by the means (54) extraction on the volume (V) of the industrial premises (16) which, for a given unit operating time, is greater than or equal to 1.

8. An assembly according to claim 7, characterized in that the extraction means (54) are controlled so as to establish a factor (F) between 2 and 20.

9. A method of recycling air in an assembly for the production of containers which comprises a building comprising a closed industrial premises (16) delimiting a volume (V) of ambient air, and an installation (10) for the manufacture of containers (12) from preforms (14) which is implanted in the industrial premises (16), the recycling process comprising at least the steps consisting successively of:

(a) filtering ambient air to obtain filtered air used to air-cool at least a portion of the preforms (14) during thermal conditioning in an oven (26) of the plant (10); );

(b) extracting filtered air out of the oven (26) after using said air for cooling;

(c) recycling at least a portion of said filtered air extracted from the furnace (26) by reintroducing at least a portion of said air into said industrial premises (16).

10. Process according to claim 9, characterized in that the recycling process comprises at least one step consisting of:

- control the extraction means (54) for establishing a loop air circulation between the volume (V) of the industrial space (16) and a zone (20) inside the oven (26) with a factor ( F) corresponding to the ratio of the volume (Ve) of air extracted from said zone (20) of the oven (26) by the extraction means (54) on the volume (V) of the industrial space (16) which, for a given unit operating time, greater than or equal to 1.